Urinary Bladder Injuries
Bladder injuries occur as
a result of blunt or penetrating trauma. The probability of bladder injury
varies according to the degree of bladder distention; therefore, a full
bladder is more likely to become injured than an empty one.
Although uniformly fatal in the past, a timely
diagnosis with appropriate medical and surgical management now offers an
excellent outcome. Early clinical suspicion, appropriate and reliable radiologic
studies, and prompt surgical intervention, when indicated, are the keys
to successful diagnosis and management.
History of the Procedure:
Patients with signs and symptoms suggestive of
a bladder injury have a history typical for pelvic trauma, which is fairly
straightforward for motor vehicle accidents, deceleration injuries, or
assaults
to the lower abdomen. If the patient is unconscious,
family members or, more often, emergency services personnel can provide
the history.
Bladder injury from a motor vehicle accident
may occur from direct impact with the car or indirectly from the steering
wheel or seatbelt.
Deceleration injuries of the urinary bladder
usually result from falling from a great height and landing on unyielding
ground.
Assault to the lower abdomen by a sharp kick
or blow may result in a bladder perforation.
Penetrating injuries to the bladder usually result
from high-velocity gunshots or sharp stab wounds to the suprapubic area.
Problems:
Blunt trauma
Deceleration injuries usually produce both bladder
trauma (perforation) and pelvic fractures. Approximately 10% of patients
with pelvic fractures also have significant bladder injuries. The propensity
of the bladder to sustain injury is related to its degree of distention
at the time of trauma.
Penetrating trauma
Assault from a gunshot or stabbing typifies penetrating
trauma. Often, concomitant abdominal and/or pelvic organ injuries are present.
Obstetric trauma
During prolonged labor or a difficult forceps
delivery, persistent pressure from the fetal head against the mother’s
pubis can lead to bladder necrosis. Direct laceration of the urinary bladder
is reported in 0.3% of women undergoing a cesarean delivery. Previous cesarean
deliveries with resultant adhesions are a risk factor. Undue scarring may
cause obliteration of normal tissue planes and facilitate an inadvertent
extension of the incision into the bladder. Unrecognized bladder injuries
may lead to vesicouterine fistulas and other problems.
Gynecologic trauma
Bladder injury may occur during a vaginal or
abdominal hysterectomy. Blind dissection in the incorrect tissue plane
between the base of the bladder and the cervical fascia results in bladder
injury. Women with no history of pelvic radiation are at higher risk.
Urologic trauma
Perforation of the bladder during a bladder biopsy,
cystolitholapaxy, transurethral resection of the prostate (TURP), or transurethral
resection of a bladder tumor (TURBT) is not uncommon. Incidence of bladder
perforation is reportedly as high as 36% following bladder biopsy.
Orthopedic trauma
Orthopedic pins commonly perforate the urinary
bladder. Thermal injuries to the bladder wall may occur during the setting
of cement substances used to seat arthroplasty prosthetics.
Idiopathic bladder trauma
Patients diagnosed with alcoholism and those
individuals who chronically imbibe a large quantity of fluids are susceptible
to this type of injury. Previous bladder surgery is a risk factor. In reported
cases, all bladder ruptures were intraperitoneal. This type of injury may
result from a combination of bladder overdistention and minor external
trauma (eg, a simple fall).
Frequency:
Frequency of bladder rupture varies according
to the following mechanisms of injury:
External trauma (82%)
Iatrogenic (14%)
Intoxication (2.9%)
Spontaneous (<1%)
Of all bladder injuries, 60-85% are from blunt
trauma and 15-40% are from a penetrating injury. The most common mechanisms
of blunt trauma are motor vehicle accidents (87%), falls (7%), and assaults
(6%). In penetrating traumas, the most frequent culprit is gunshot wounds
(85%), followed by stabbings (15%).
Approximately 10-25% of patients with a pelvic
fracture also have urethral trauma. Conversely, 10-29% of patients with
posterior urethral disruption have an associated bladder rupture.
Traumatic bladder ruptures
Of traumatic ruptures, extraperitoneal bladder
perforations account for 50-71%, intraperitoneal accounts for 25-43%, and
combined perforations account for 7-14%. Incidence of intraperitoneal bladder
ruptures is significantly higher in children because of the predominantly
intra-abdominal location of the bladder prior to puberty.
Combined intraperitoneal and extraperitoneal
ruptures account for approximately 10% of all traumatic bladder-perforating
injuries. Mortality rates in these patients approach 60%, as compared to
17-22% overall, reflecting the severity of concomitant injuries associated
with combined bladder ruptures.
Associated bowel injuries
Incidence is reportedly as high as 83% in patients
with gunshot wounds. Colon injuries are reported in 33% of patients with
stab wounds, and vascular injuries are reportedly as high as 82% in patients
with a penetrating trauma (with a 63% mortality rate).
Etiology:
Main causes of bladder injury are penetrating
and blunt trauma. Iatrogenic causes include surgical misadventures from
gynecologic, urologic, and orthopedic operations near the urinary bladder.
Less common causes involve obstetric trauma. Spontaneous or idiopathic
bladder injuries without an obvious underlying pathology constitute the
remainder.
Pathophysiology:
Bladder contusion is an incomplete or partial-thickness
tear of the bladder mucosa. A segment of the bladder wall is bruised or
contused, resulting in localized injury and hematoma. Contusion typically
occurs in the following clinical situations:
Patients presenting with gross hematuria after
blunt trauma and normal imaging studies
Patients presenting with gross hematuria after
extreme physical activity (ie, long-distance running)
The bladder may appear normal or teardrop shaped
on cystography. Bladder contusions are relatively benign, are the most
common form of blunt bladder trauma, and are usually a diagnosis of exclusion.
Bladder contusions are self-limiting and require no specific therapy, except
for short-term bed rest until hematuria resolves. Persistent hematuria
or unexplained lower abdominal pain requires further investigation.
Extraperitoneal bladder ruptures
Traumatic extraperitoneal ruptures usually are
associated with pelvic fractures (89-100%). Previously, the mechanism of
injury was believed to be from a direct perforation by a bony fragment
or a disruption of the pelvic girdle. It is now generally agreed that the
pelvic fracture is likely coincidental and that the bladder rupture is
most often due to a direct burst injury or the shearing force of the deforming
pelvic ring.
These ruptures usually are associated with fractures
of the anterior pubic arch, and they may occur from a direct laceration
of the bladder by the bony fragments of the osseous pelvis. The anterolateral
aspect of the bladder typically is perforated by bony spicules. Forceful
disruption of the bony pelvis and/or the puboprostatic ligaments also tear
the wall of the bladder. The degree of bladder injury is directly related
to the severity of the fracture.
Some cases may occur by a mechanism similar to
intraperitoneal bladder rupture, which is a combination of trauma and bladder
overdistention. The classic cystographic finding is contrast extravasation
around the base of the bladder confined to the perivesical space; flame-shaped
areas of contrast extravasation are noted adjacent to the bladder. The
bladder may assume a teardrop shape from compression by a pelvic hematoma.
Starburst, flame-shape, and featherlike patterns also are described.
With a more complex injury, the contrast material
extends to the thigh, penis, perineum, or into the anterior abdominal wall.
Extravasation will reach the scrotum when the superior fascia of the urogenital
diaphragm or the urogenital diaphragm itself becomes disrupted.
If the inferior fascia of the urogenital diaphragm
is violated, the contrast material will reach the thigh and penis (within
the confines of the Colles fascia). Rarely, contrast may extravasate into
the thigh through the obturator foramen or into the anterior abdominal
wall. Sometimes, the contrast may extravasate through the inguinal canal
and into the scrotum or labia majora.
CT Scan
This is often the first test performed
on patients with blunt abdominal trauma. Although CT scan of the pelvis
provides information on the status of the pelvic organs and osseous pelvis,
static cystogram is superior in the diagnosis of bladder ruptures.
Relevant Anatomy:
The adult bladder is located in the anterior
pelvis and is enveloped by extraperitoneal fat and connective tissue. It
is separated from the pubic symphysis by an anterior prevesical space known
as the space of Retzius. The dome of the bladder is covered by peritoneum,
and the bladder neck is fixed to neighboring structures by reflections
of the pelvic fascia and by true ligaments of the pelvis.
In males, the bladder neck is contiguous with
the prostate, which is attached to the pubis by puboprostatic ligaments.
In females, pubourethral ligaments support the bladder neck and urethra.
The body of the bladder receives support from
the urogenital diaphragm inferiorly and the obturator internus muscles
laterally.
The superior fascia of the urogenital diaphragm
is continuous and includes the pelvic, obturator, and endopelvic fasciae.
The inferior fascia of the urogenital diaphragm fuses with the Colles fascia.
It continues as the Scarpa fascia anteriorly, the dartos muscle and fascia
in the scrotum, and the fascia lata of the thigh.
The type of extravasation (intraperitoneal or
extraperitoneal) depends upon the location of the laceration and its relationship
with the peritoneal reflection.
If the perforation is above the peritoneal reflection,
the extravasation is intraperitoneal.
If the injury is below the peritoneal reflection,
the extravasation is extraperitoneal.
With an anterosuperior perforation, urinary extravasation
may be intraperitoneal, extraperitoneal (space of Retzius), or both. If
the tear is posterosuperior, fluid can spread intraperitoneally and/or
retroperitoneally.
In a bladder rupture, the superior fascia of the
urogenital diaphragm, when intact, prohibits extravasation from escaping
the pelvis. Inferior fascia of the urogenital diaphragm, when intact, also
prevents urinary extravasation from flowing into the perineum.
Coauthored by
Coauthored by Benjamin Battino, MD, Staff Physician,
Department of Surgery, Division of Urology, University of Cincinnati College
of Medicine
Jong M Choe, MD, FACS, is a member of the following
medical societies: American Association
of University Professors, American
College of Surgeons, American Medical Association, American Urological
Association, MedChi, Ohio State Medical Association, and Ohio Urological
Society
Edited by Toby C Chai, MD, FACS, Assistant Professor,
Department of Surgery, Division of Urology, University of Maryland School
of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine;
Shlomo Raz, MD, Professor, Department of Surgery, Division of Urology,
University of California at Los Angeles School of Medicine; J Stuart Wolf,
Jr, MD, Director of Michigan Center for Minimally Invasive Urology, Associate
Professor, Department of Urology, University of Michigan Medical Center;
and Stephen W Leslie, MD, FACS, Founder and Medical Director of the Lorain
Kidney Stone Research Center, Assistant Clinical Professor, Department
of Urology, Medical College of Ohio